Harold m



H.YIVI. PLAISTED. Renucm MILL. APPLICATION FILED FEB. 3,1919. 1,322,339.Patented Nov. 18, 1919.

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HAROLIO M. PLAISTED, OF ST. LOUIS, MISSOURI, ASSIGN' OR T'O WILLIAMSPATENT CRUSHER.ANDPULVERIZER CO., ST. LOUIS, MISSOURI, A CORPORATION OF:i/rIssoUitr.-

T0 all whom t may concern:

Be it known-that ll', HAROLD PLAisTED, a citizen of the United States,residing at St. Louis, State of Missouri, have invented certain new anduseful Improvements in Reducing-Mills, of which the following isaspe'ciication. L.

This invention relates to certain new and usefull improvements inreducing mills for feed and like material.

The main object of my invention is to provide rotary pivoted means forcutting the feed, as distinguished from pounding or beating it, and tothrow the feed forward into the pathof the hammers and outward againstthe cage. Another object is to provide a by-pass for catching metal,gravel,

. .and Vlike.foieign matter, that the hammers throw outward with thefeed, and separate ing the foreign matter while allowing the feed toreturn to thecage.

In the accompanying drawing on l,which like reference letters indicatecorresponding parts, .Figure 1 represents a reducing mill illustratingvmy invention, the view being a sectional elevation across the shaft; andFig. 2 a detail perspective view of a preferred form of hammer asmounted in said mill.

The letter A designates the shaft of a mill 'of the character described,onV which are mounted end disks B carrying hammer rods C on which arepivotally mounted stirrup hammers by their legs D-D,-the inner ends ofwhich are provided with holes'E for said hammer rods.

The outer ends of said legs are shaped to a point lying substantially ina radial plane through the pivot and shaft and these points areconnected by a cross bar F which is of the shape of a portionof acylinder with the concave face toward the front', and said portion ofthe cylinder lying approximately in the radial plane through vthepivotal points 'of the legs and center of the shaft. The normal positionof the outer edge of the cross bar at the front face is slightly infront of said radial plane,v and is chamfered from said outer'edgebackward to the rear to give clearance for the cutting edge thusproduced. rThe inner side face of said 'bar is practically at rightangles to the radial plane through the pivots and the centferof'gra'vity `of the hammer when rotating,

and meets the front face in an acute angle that facilitates passingthroughx` the feed REDUCING-MILL.

Specification of Letters Patent. Patented-NOV. 18, 1919 AppiioaiionmedFebruary e, 191e. serial No. 274,678.

being operated on, after the` curved front face engages the material infront of it and acts upon it in the following manner. The inner edge ofsaid cross bar is preferably a farther distance `in 4front of saidradial plane than the outer edge; and on account of the concave shape'ofthe front face and the normal position of the hammer in operation, thematerial being operated on is cleared from the cutting edge by thebackward and inward slope of the outer portion of the front face, and istheir thrown outward again toward the cage by the reversely curved outerportion of said front face.

The rear face of the bar is convex, being preferably curved concentricwith the front face, and together with the outer and inner side faces,constituting a bar that is coniparatively thin in the direction ofrotation and pressure, and the forwardly projecting outer and innersidesof the bar due to 'its curved form, increase its stiffness while theyalso cut through the'material; and when this '4 jacent to the cage.V Inpractice, this stirrup hammer has been made in vcast steel and thecurved cross bar has been provided Vith a strengthening rib f at therear and near the center, and the hardened steel face plate has beenriveted in the recess as shown on the drawing. If desired,'however, theface plate may be omitted and the hammer be cast in manganese steel, orother suitable material according to requirements. It is preferredhowever to provide La comparatively softvmetal for the body of thehammer and vfasten to the front face the concave cutting blade, which isreversible so that the cutting .edge when worn may be replaced byreversing the blade in the recess.

The kcage G is of perforated metal but may be otherwisefornied. Thehousing of the mill is provided with a suitable hopper H, ,andregulating slide l supported 'by a slanting wall J forming one side ofthe hopof said cage is conveniently fastened. The

Y back wall M of the housing extends upward from the said opening K, anda topwall N extends from the back wall forward, at about an angle of 45degrees withfthe verv tical, to its connection with the reverselysla/nting wall J. An inner4V partition wall Ofextends upward from saidopening K and parallel to the back wall M, but not reaching the top wallN. A vertical guiding-passage is thus formed from the opening K,

and a pocket R is formed by the partition wall O' and the upper portionof the cageV adjacent and between 'the openings K andL, which openingsvtogether with the guiding and detiecting walls described, constitute aby-pass with the intermediate pocket. Thel rotation of the liammers'iny'the direction of the arrow tends to drive the feed outward and upwardthrough the vertical passage between the walls M and O, and it isdefiected horizontally over the top of the partition O by the slant wallN, and then down- .ward into said pocket bythe slant wall J. rIhe pocketwill naturally lill up with the feed and contained matter that isforeign to the feed, such as metal and gravel, but the surplus materialwill iow inward againthrough the opening L after the natural slope ofmaterial is formed in the pocket as indicated in Fig. l. Any metal willf be driven into the feed material and gravitate to the lower angle ofthe ocket above the cage and toward the wall The perforations in thecage that forms the bottom of said pocket, willy allow a sifting of thefeed materiall backward to the cage, but will retain the metal andgravel and like foreign matter in the pocket. e f" The top froin theback wall M is `preferably removable to form a door,-such as byproviding hinges P at its lower side edge connecting f it to the backwall, and a suitablefastening such as a button Q, for the top edge. i

I claim: A mill of the character described comprising a cage havingl anoutlet opening and an inlet opening for a 'by-pass, and a casing havingwalls forming a by-pass connecting said cage openings, and having arecess pocket in the lower side of said by-pass for catching metalparticles, and a removable door giving access to said pocket.

2. A mill of the character described comprising a casing having guidingand'deiecting and partition wallsforming a by-pass,

wall N that is slanting forward* receive the pivoting means,

- and a 'cage `forming with 'said partition wall plane-fa backrwall anda partition wall'V forming, a verticalpassage communicating with saidoutlet, a top wall inclined toward said partition, a reverselyinclined-wall in, front of said partition, and a pocket'belowthereversely inclined wall `.and adjacent ,tol said inlet opening,substantially asrdescribed. 4. In a mill of the character described ahammer carrier and a shaft therefore, a hammer pivot on the carrierwithits axis parallel to tlie-fshafts axis; and a cutting hammer pivotedon the pivot and'having its greatest Vradial length from its own pivotin its longitudinal medial planeso that in action its cutting edge movesin its nearest position to the cage of the mill and in rearward movementofy he hammer on its Ainner pivot causes its edge to recede from'thecage; the cutting edge being in the radial .plane of greatest length,the cutting hammer having a transverse bar which is concaved on its facetransversely from end' to end, the inner edge of the concave beingl inadvance from the outer or cutting edge.

5. In a mill of the character a hammer adapted to be pivoted on an `axisparallel to the main shaft of the mill and having a pair of spaced sideor end arms to receive the pivoting means, and a transverse tieconnecting the swinging ends of the arms and being concaved on its frontfacel ,from end to end, thevouter longitudinal or `toe edge of the barbeingclose to the medial,

axial plane of the arms and the heel or inner,

longitudinal, front edge of the bar being in a' plane in advance of thetoe edge.

described,

6. In a mill of the character described, a

hammer adapted to be pivoted on an axis parallel to the main shaft ofthe mill and having a pair of spaced sidev or end arms to and atransverse tie connecting the swinging ends of the arms and beingconcaved on its front face from end to Aend, the outer longitudinal ortoe edge of the bar being close to the medial axial plane of the armsand the heel or inner, longitudinal, front edge of the bar being in aplane in advance of the toe edge, anda cutting blade mounted on thelface of the bar. .y y

In testimony whereofJ I have aixed my sgnatue.

